نتایج جستجو برای: Pyrano [3
تعداد نتایج: 1811585 فیلتر نتایج به سال:
Starting from commercially available educts, a straightforward synthetic route to new heterocyclic building blocks is exemplified with the one- or two-step synthesis of tri-, tetra-, or pentacyclic ring systems. Representatives of the following novel ring systems are prepared from 3-methyl-1-phenyl-2-pyrazolin-5-one and the corresponding o-halo-arenecarbonyl chloride using calcium hydroxide in ...
Several novel naphtho[2,1-b]pyrano[2,3-d]pyrimidines, pyrano[3,2-e][1,2,4]triazolo[1,5-c]pyrimidines and their coumarin-3-yl derivatives were synthesized. Some of these derivatives exhibited pronounced antimicrobial activities.
The title compound, C(19)H(15)NO(2)S(3), is the first example of a dithia analogue of pyrano[3,4-b]indolone. The almost planar thio-pyrano-indole-thione ring system (r.m.s. deviation for all non-H atoms = 0.030 Å) makes a dihedral angle of 80.70 (8)° with the p-tolyl ring. In the crystal, mol-ecules are connected via C-H⋯O hydrogen bonds into two chains along the b axis. These chains are connec...
A new molecule of 2-[3, 4 di hydroxy phenyl] 3, 5, 14-trihydroxy 13oxo 2H-chromeno [34:5, 6] pyrano [2, 3-h] 4H-chromene 4-one was synthesized and screened. This new compound was synthesized by incorporating 4-chloro-3-formyl coumarin group with quercetin compound. In the present study the antioxidant and antimalarial activities of new 2-[3, 4 di hydroxy phenyl] 3, 5, 14-trihydroxy 13oxo 2H-chr...
The title compound, C(20)H(15)N(5)O(3), was synthesized by the one-pot reaction of a four-component reaction protocol in aqueous medium. The pyrano[2,3-c]pyrazole system is essentially planar, with a maximum deviation of 0.026 (2) Å. The 3-nitro-phenyl and phenyl rings make dihedral angles of 81.11 (5) and 13.36 (1)°, respectively, with the mean plane of the pyrano[2,3-c]pyrazole ring. The crys...
Pyrano[2,3-c]pyrazoles are obtained via mixing ethyl acetoacetate, hydrazine hydrate, aldehydes or ketones and malononitrile in the absence of solvent. These same products were also obtained by reacting arylidenemalononitriles 3 with 3-methyl-2-pyrazolin-5-ones. NOE difference experiments confirmed that these products exist solely in the 2H form. Similar treatments of 3-amino-2-pyrazolin-5-one ...
The bifunctional pyrazolopyridine (2) and pyrano-pyrazole (3) derivatives were prepared by the reaction of 2-(2,4-dinitrophenyl)-5-methyl-2,4-dihydro-3H-pyrazol-3-one (1) with p-methoxybenzaldehyde, malononitrile in the presence of ammonium acetate or piperidine, respectively. Compound 2 was used as the key intermediate to prepare the pyrazolo-pyrido-pyrimidine derivatives through its reaction ...
an electroorganic reaction for the synthesis of 7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1h-pyrano[2, 3-d] pyrimidine-6-carbonitrile and ethyl-7-amino-2, 4-dioxo-5-phenyl-2,3,4,5-tetrahydro-1h-pyrano[2, 3-d] pyrimidine-6-carboxylate derivatives are described, using an electrogenerated base of the anion of malonitrile or ethylcyanoacetate. this one-pot, three-component condensation of an a...
A series of naphthopyran derivatives 3a-f were prepared. Reaction of 2-amino-4-(p-chlorophenyl)-7-methoxy-4H-naphtho[2,1-b]pyran-3-carbonitrile (3b) with Ac2O afforded two products, 2-acetylamino-7-methoxy-4-(p-chlorophenyl)-4H-naphtho-[2,1-b]pyran-3-carbonitrile (4) and 10,11-dihydro-3-methoxy-9-methyl-12-(p-chloro-phenyl)-12H-naphtho[2,1-b]pyran[2,3-d]pyrimidine-11-one (5) and treatment of 3b...
A copolymer donor PBDTTPTP based on a tetracyclic bislactone unit, thieno[2',3':5,6]pyrano[3,4-d]thieno[3,2-b]pyran-4,9-dione (TPTP), was developed. The single crystal structure of TPTP derivative indicates the π-extended planar geometry and...
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